CO2 capture and sequestration is one of the only feasible means for significantly reducing CO2 emissions from coal-fired power plants. One promising method of carrying out CO2 capture is the use of dry adsorbents in a temperature swing process. Potential sorbents are being developed and evaluated extensively in the industry.
One of the most common types of solid adsorbents are those that are functionalized with an amine. Within the subset of supported amines, one material of interest is an ion-exchange resin that has been functionalized with an amine. It is known to use an adsorption temperature of 20° C. to 30° C. and regeneration temperatures in the range of 80° C. to 100° C. for amine functionalized ion-exchange resins.
Although sorbents that utilize an amine have demonstrated promising traits related to CO2 capture, the upper bounds of regeneration temperature have been low because amines tend to degrade at elevated temperatures. Adsorption and regeneration conditions affect the overall cost for CO2 capture. Operating a CO2 capture system within previously disclosed temperature ranges of 20° C. to 30° C., with regeneration temperatures of 80° C. to 100° C., results in a significant energy penalty due to the required cooling of flue gases.
A need therefore exists in the art for an amine-based sorbent having superior degradation characteristics that can withstand higher operating temperatures.